I would guess that is a composite photograph constructed to appear as an optical illusion. Notice that there is no shadow on the graph paper from the odd cross bar at it's end on the right side of the picture. As xraan states, the shadow is indicated from that crossbar as it exits the left upright and is at about a 45 degree angle.. Someone has photographed that bar placed in the left side, then photgraphed it placed in the right side upright and then joined the two, probably in a computer program rather than cutting and pasting two photos... This is supported if you look at the floor at the rear of the object. There's a power cord or some such, running from the right side of the picture to to the left, however, there's a gap in the cord just before is ascends to it's attached object. This is another indication of a cleverly faked composite. They didn't position the composite exactly right to assure joing the two pictures at the power cord junction...